1. Technical Field
This invention relates to devices for making electrical connections between conductors and more particularly to improved devices which reliably grip and align the conductors in wire-retaining slots to ease the splicing operation and assembly of such devices.
2. Description of the Prior Art
Connectors of the type disclosed in U.S. Pat. No. 3,772,635, issued Nov. 13, 1973, to Frey et. al. systemize cable splicing work and are universal in that they can accommodate a wide size range of conductors. In the basic splice unit, the connector disclosed in Frey et al comprises an index strip with wire-retaining slots for receiving individual insulated conductors or wires, a connector module with double-ended slotted beam contact elements and an index-strip portion, and a module cap.
The index strip separates conductors of a first group with slot-defining upright members and acts as a temporary wire holder preparatory to splicing. The index-strip portion of the connector module is similar to the index strip and operates to index and hold conductors of a second group. Each slotted beam contact element connects a conductor in the first group with the associated conductor in the second group.
Normally, the connector is assembled with a tool and holder such as described in Frey et al. Each of the three connector components includes along their end walls vertical grooves which fit guiding tabs in the holder.
In assembling the connector disclosed in Frey et al, a splicer first mounts the index strip onto the holder through the guiding tabs. With the slot-defining members, which alternate in height to provide additional visual and physical guidance, the splicer then locates the conductors into their separate wire-retaining slots. Then the head of the tool is applied to the strip, snubbing the conductors down into position and severing the conductors at the rear end of the wire-retaining slots. Then the connector module is placed into the same guiding tabs of the holder and pressed down sufficiently so that it snap-mounts onto the index strip. At that time the slotted beam contact elements also make electrical engagement with the conductors in the index strip. Then the second group of wires are similarly indexed, snubbed and severed. During the snubbing, the conductors in the connector module engage the slotted beam contact elements. Finally, the cap is mounted via the same guiding tabs and snap-mounted onto the module to complete the basic splice.
While the connector disclosed in Frey et al has proven satisfactory for the most part, certain improvements have been found desirable. Various improvements can be made to render the prior art connector even more reliable and efficient in terminating conductors of different sizes, and less craft-sensitive.
One aim is to minimize the effects of axial loads which cause conductors to pull out from the front side of the index strip or index-strip portion, especially after the conductors are snubbed and severed at the rear end of the wire-retaining slots.
Another aim is to permit accommodation of a greater size range of conductors in the wire-retaining slots without reducing reliability and splicing efficiency. Desirably smaller conductors, as well as larger conductors, are precisely aligned and centered in their respective wire-retaining slots during indexing for snubbing and for engaging their assigned slotted beam contact element.
Another aim, especially with the larger conductors, is to hold the conductors so that they do not pop back out vertically, opposite to the direction they are put in.
A further aim is to increase the electrical isolation between the exposed ends of the conductors within each group. The larger conductors are especially more prone to electrical leakage since they are physically closer to one another than are the smaller conductors, given the same wire-retaining slot spacing.